1. Field of the Invention
This invention relates generally to a device for separating particles having different specific densities from each other. It has specific application in the separation of coal from other materials.
2. Description of the Prior Art
A common problem of known prior art devices has been that they fail to completely separate the desired materials from the undesired materials. Another problem has been that in the case of water or liquid being used in the process of separation, large quantities of same have been required. This in many instances has limited the use of the devices to areas where large quantities of water are readily available. It is highly desirable to have a separator which will almost completely remove the debris material from the desired material and also be conservative of the use of the liquid involved.
The prior art teaches a number of different types of separators such as the rubber separator to Askam, U.S. Pat. No. 572,854 and the patent to Phipps, U.S. Pat. No. 3,456,789 for grading solid particles in a liquid suspension. Other known patents for separating classifying ores or a liquid suspension are taught by U.S. Pat. Nos. 327,766; 1,163,876; 1,511,643; 2,533,074; 2,919,024; and 2,696,298. None of these separators teach the new and novel device as disclosed by this invention.
Other known separators specifically for use in separating coal from other debris are taught by U.S. Pat. Nos. 528,803; 1,737,410; 2,058,374; 2,823,801; 2,521,152; and 2,660,305. Known prior art involving separation by the use of air or vacuum are shown in U.S. Pat. Nos. 447,027; 3,250,389; 3,374,505; 3,685,651; and 3,804,245. While the above-listed patents may be pertinent to the disclosed invention, none of them show the combination as disclosed in this application.